When the sunlight hits the panel, the electrons move around and create electricity. This electricity then goes through wires that are connected to the panel.
Very informative video (too bad we can't use YouTube during school!):
Two types: Thermal: solar energy -> heat
Photovoltaic: solar energy -> electricity
Solar Energy is not very efficient. For example, the average photovoltaic (PV) panel is only around 20% efficient. However, silicon designs are around 40% efficient. While some scientists have discovered solar panels that are up to 80% efficient, the current focus is on making the panels cheaper.
Although the Earth absorbs about 3,850,000 exajoules of solar energy every year, it is not always available. For instance, there is no solar energy at night. However, batteries can be attached to store excess sunlight that is absorbed during the day. Also, many areas far from the equator undergo periods in which there is no sunlight for many days. However, solar energy is abundant. The amount of solar energy that hits the Earth in one hour is greater than the amount that the world uses in one year.
Overall, solar energy is very good for the environment. It is a renewable resource which limits the amount of greenhouse gases emitted into the atmosphere. Although solar power doesn't pollute while it is in operation, the process by which solar panels are made does produce some pollution. However, this pollution is minimal compared to the amount of pollution that is saved by using solar power.
Solar Energy
by Daniel Weiner and Mark Schneider1. How is it obtained?
When the sunlight hits the panel, the electrons move around and create electricity. This electricity then goes through wires that are connected to the panel.
Very informative video (too bad we can't use YouTube during school!):
Two types:
Thermal: solar energy -> heat
Photovoltaic: solar energy -> electricity
http://www.eia.doe.gov/fuelrenewable.html
This is what a solar panel looks like:
2. How efficient is it?
Solar Energy is not very efficient. For example, the average photovoltaic (PV) panel is only around 20% efficient. However, silicon designs are around 40% efficient. While some scientists have discovered solar panels that are up to 80% efficient, the current focus is on making the panels cheaper.
http://poweredbysolarpanels.com/solar-panel-efficiency
3. How available is it?
Although the Earth absorbs about 3,850,000 exajoules of solar energy every year, it is not always available. For instance, there is no solar energy at night. However, batteries can be attached to store excess sunlight that is absorbed during the day. Also, many areas far from the equator undergo periods in which there is no sunlight for many days. However, solar energy is abundant. The amount of solar energy that hits the Earth in one hour is greater than the amount that the world uses in one year.
http://www.energy-consumers-edge.com/pros_and_cons_of_solar_power.html
http://www.ehow.com/about_5518265_availability-solar-energy.html
http://www.solarenergy.org/younger-kids
Solar power potential:
4. How much does it cost?
Although the initial cost of solar energy is very high, it ends up being cost effective in the long run.
Initial costs for various solar panels:
Panel
Manuf.
per Watt
(US $)
(US $)
5. What are the environmental impacts?
Overall, solar energy is very good for the environment. It is a renewable resource which limits the amount of greenhouse gases emitted into the atmosphere. Although solar power doesn't pollute while it is in operation, the process by which solar panels are made does produce some pollution. However, this pollution is minimal compared to the amount of pollution that is saved by using solar power.
http://www.facts-about-solar-energy.com/solar-energy-advantages-disadvantages.html
http://www.ucsusa.org/clean_energy/technology_and_impacts/impacts/environmental-impacts-of.html
Solar Energy Pros:
- Little to no pollution
- Quiet
- Able to be used easily in rural areas
- More cost effective over time
- Compact and easily placed on roofs
- Renewable
Solar Energy Cons:http://www.clean-energy-ideas.com/articles/pros_and_cons_of_solar_energy.html
http://seniord.ee.iastate.edu/may0616/website/solar2.htm
Other Good Websites
http://www.energyquest.ca.gov/story/chapter15.html
http://tonto.eia.doe.gov/kids/energy.cfm?page=solar_home-basics-k.cfm
http://www.eia.doe.gov/fuelrenewable.html
http://environment.nationalgeographic.com/environment/global-warming/solar-power-profile/
http://ngm.nationalgeographic.com/2009/09/solar/johnson-text
http://www.scientificamerican.com/article.cfm?id=how-does-solar-power-work